Gelatin and glue extractor



Jan. 28, 1936. w. v. KNOLL GELATIN AND GLUE EXTRACTOR Filed June 6, 1932 3 Sheets-Sheet 1 Jan. 28, 1935. w v KNOLL GELATIN AND GLUE EXTRACTOR Filed June 6, 1932 3 Sheets-Sheet 2.

393% r W. v. KNGLL 2038,2935

GELATIN AND GLUE EXTRACTOR Filed June 6, 1932 3 Sheets-Sheet 3 Patented Jan. 28, 1936 uru'rsp STATES PATENT OFFICE GELA'IIN AND GLUE EXTBACTOR 7 William v. Knoll, Dayton, Ohio Application June 6, 1932, Serial No. 615,640

'7 Claims. .(Ol. 87-13) This invention relates to rendering apparatus for animal matter, and more particularly to an extractor for treatment of hides, skins and bones in the production of gelatin and glue, but which is also applicable to reduction of packing house and fishery oifal for recovery of by-products in the manufacture of fertilizer.

. Gelatin for edible purposes as well as for industrial use, photographic dry plates and paper, medical, and bacteriological purposes as well as for the manufacture of glue is derived from hidestock, trimmings and fleshings, including sheep pates, cattle and calf hides, rabbit skins, and the ossein of bones, horn piths and button bones by a process of cooking at relatively low temperatures of 130 to 200 degrees Fahrenheit which serves to break down the structure of the material and release the fat or tallow which rises to I .the top of the liquor and is removed'as a byproduct, and at the same time dissolves the soluble gelatinous matter in the cooking water which is drawn off for concentration by evaporation, chilling, spreading, drying and finishing or grinding.

The more desirable gelatin of lighter color and greater translucency is that extracted at lower temperatures known in the industry as first run liquor.

The subsequent recooking of the material at higher temperatures results in additional extractions of the gelatinous material, but of lower quality, ordinarily designated as second,

third and fourth run liquors, the cooking tem-' perature of each being higher than the preceding. While various forms of apparatus have been heretofore devised for the present purpose, the

industry is yet dependent generally upon very crude and primitive methods of reducing the stock by cooking it in open wooden vats having steam coils in-their bottoms over which wood excelsior and sticks are laid to support the cooking mass of material, which is hand stirred from time to time by prying it up and turning it about by means of a paddle or fork. The grease released during such cooking operation is hand skimmed as it rises to the top. By such method it is quite difficult to maintain a, constant and uniform temperature of the cooking water although this is a highly important factor in the production of high quality gelatin. Due to the fact that the liquid does not uniformly penetrate the mass, the gelatin is not thoroughly extracted and long cooking is required resulting in deterioration of the prodnot and the necessity for a large number of cooking vats. The residue of such method usually contains a considerable quantity Oi available grease which must be removed in a filter press or by gasoline or similar extraction. In any event, however, such methods result in loss of considerable gelatin and grease.

The object of the present invention is to 1m 5 prove the apparatus as well as the method and mode of operation of extracting gelatin from hidestock, bones, and the like, whereby such apparatus will not only be simple in construction and economical for manufacture, but will be more eflicient in use, semi-automatic infoperation, uniform in action, convenient, and easily controlled, and unlikely to get out of repair. v

A further object of .the invention is to provide a process and apparatus for performing the extracting operation in a simplified manner and adapted to produce gelatin or glue of greatly improved quality with respect to adhesive or binding strength, color and transparency.

A further object of the invention is to effect comparatively complete extraction of the grease or tallow during the cooking operation thereby avoiding the necessity of mechanical or chemical methods necessary. for extraction of remaining grease in the stock residue.

A further object of the invention is to provide apparatus and a method for eifecting a much greater recovery of the available gelatin during the first run operation, which, due to lighter color and greater transparency, be of greater commercial value. v

A further object of the invention is to provide apparatus which will minimize the use of hand labor and which will economize in the use of steam for heating the liquor and stock.

A further object of the invention is to provide means whereby a constant and uniform temperature will be maintained at all times throughout the mass of stock and whereby the stock will be uniformly agitated, thus hastening the cooking operation, and at the same time afford a more highly concentrated first run liquor thereby avoiding or at least minimizing the necessity for evaporation which'also affects undesirably the quality and commercial value of the product.

With the above primary and other incidental objects in view, as will more fully appear in the specification, the invention consists-of the fea- Fig. '1 is a longitudinally sectional view of the assembled apparatus, forming the subject matter hereof. Fig. 2 is an end elevation, and Fig. 3 is a top plan view thereof. Figs. 4 and 5 are respectively' an end view and plan view somewhat diagrammatically illustrating a modification of the construction heretofore described. Figs. 6, 7, and 8 illustrate further modifications.

Like parts are indicated by similar characters of reference throughout the several views.

As before mentioned, gelatin is extractedfrom hidestock, that is, sheep and calf pates, hide trimmings and fieshings, rabbit skins and ossein which is the organic substance contained bone. The bones are not employed in a natural or raw state, but undergo a preliminary treatment wherein they are washed, crushed and degreased and are then subjected tomaceration for extraction of the mineral substance by means of diluted acid, thereby producing as a 'ey-product acid phosphate. The ossein resulting from the treat-- ment of the bones together with the hide stock or other animal matter is then introduced into steeping vats where it is washed and treated with lime or caustic soda which causes the material to swell. After liming, the material is further washed and treated by an acid bath to neutralize the alkali and bleach the raw stock which is again washed to a neutral condition. It is highly important that the water used for washing purposes as well as cooking shall be soft and substantially free from lime, magnesia, carbonates or sulphates .2, such shape is not essential although desirable.

The tank I is provided with terminal walls or heads 3, and is reinforced by exterior angle bar ribs' 4 adjacent to which are disposed vertical angle bar struts 5 forming a supporting frame.

Located within the tank I is an inner compartment 6 having a semi-circular bottom I and .ver-

tical side wall 8 located in inwardly spaced relation with the side walls and bottom of the main tank or vat I and connected to its end walls 3, thereby forming an intermediate space or compartinent 9 extending about such inner compertinent. The side walls 8 of the inner compartment are perforated to provide communication between the inner compartment 6 and the outer compartment 9. The perforations may be exten'dedinto the semi-circular bottom of the compartment 6, but are preferably, though not necessarily, confined primarily to the vertical side walls 8, the lower semi-circular portion be ing preferably provided with a few more widely spaced perforations or drain holes. The bottom of the compartment 6 and preferably, though not necessarily, also the bottom of the tank I, are

- inclined longitudinally.

vment 5 intermediate the bottom of the tank i and the semi-circular bottom of the inner compartment 6, is a succession of, steam pipes or heater coils I5 having inlet and outlet connections through the tank wall for the circulation of live steam to supply the necessary cooking temperature to the contents of the tank.

, Extending longitudinally of the'tank and in substantially concentric relation with the semicircular bottom of the inner compartment 6, is a revoluble shaft I6 which may be mounted in suitable bearings upon the end walls 3 of the a tank I but which is preferably mounted in bearings I'I supported upon bearing stands id at opposite ends of the tank or which may be supported upon the tank supporting frame. Packing glands I9 are provided in the end walls 3 about the shaft I8 to prevent leakage. The shaft I6 is driven from any suitable source.

operating through suitable gear reduction mechanism to drive the shaft l6 at a relatively low rate of rotation. Carried upon the shaft I6 interlorly ofthe inner compartment 6 is an agitator device which may comprise radial arms of suitable shape and proportion, but which is preferably a rhomboidal frame comprising radially disposed spaced cross arms 2| extending different distances from the shaft IS and interconnected at their extremities by diagonally disposed bars 22 thereby forming a rotating agitator device which is inclined to its axis of rotation. As this In the drawings,- there is illustrated a driving motor 20 agitator frame rotates, it exerts a progressive action upon the material. One side of the agitator frame operates relatively deeply within the inner compartment 6' moving, turning and squeezing the material lying closely to the semicircular bottom while the opposite side of the frame in completing the rotation engages and acts upon the material less deeply. The inclined or diagonal relation of the agitator also varies the working depth at different portions of the agitator longitudinaliy of the tank. This constructlon insures thorough agitation and working of the material, keeping it in loosened condition and allowing the liquor or cooking water to reach every portion thereof uniformly. The shaft l6 and agitator device is rotated at a relatively low rate of speed of preferably, though not necessarily, two to six revolutions per minute.

While any suitable form of distributor or spray pipe may be employed for supplying fresh water to the material within the tank, in order to introduce such liquid to the center of the mass, the

shaft I6 is preferably hollow and provided with lateral discharge openings making a distributor conduit thereof to which fresh water is suppiied through a suitable connection at the end of. the shaft. By this means, water may supplied either cold or warm as conditions require. The tank is provided with suitable thermometers for indicating the temperature of the liquor therewithin so that temperatures may be uniformly and accurately controlled.

In carryi out the process, the hidestock of whatever nature, treated bones, or cssein, and other material properly washed, limed and neutralized, are placed within the inner compartment 6 through the eharging door it in the top of the tank. If such material has not been thoroughly and properly washed during the preparation, the final washing may be accomplished in the present apparatus. In such case, fresh vcold water is introduced through the hollow shaft I6 or by means of another fresh water inlet or aoaaaes distributor system and the agitator is set in operation causing the skins or hidestock to be moved about in the tank, squeezed and subjected to continual agitation. A drain outlet is provided in the bottom of the tank I which may be opened to any desired extent and as the stock within the apparatus is being washed, the water containing undesirable solids, lime, acid, or the like, is discharged from the tank through such outlet. When the washing operation has been completed, the tank is drained'of cold wash water. Thereafter, fresh warm water of a temperature somewhat below the desired cooking temperature is introduced into the tank and steam is admitted to the heater coils for raising the temperature of the water to the desired degree. The level of the liquid within the tank may be observed through the observation window or sight glass ll of the grease dome on top of the tank. When the desired level is reached the water supply is turned oh and the temperature within the tank is raised to the desired cooking temperature dependent upon the character of the material being operated upon. The heater coils are preferably provided with thermostatic control devices, not shown in the drawings, which may be set to maintain any desired temperature within the tank. As the hidestock, bones, and other material within the tank are being turned over and over by the rotation of the agitator, the gradual rise of temperature releases the grease or tallow from the stock which rises to the top ID of the tank and. then following the inclination thereof upwardly is directed into the grease dome H where it accumulates so long as there is any remaining grease or tallow in the material capable of being broken down at the temperature employed. It is quite desirable for high quality production that this grease and tallow be removed from the gelatin containing liquor at the earliest possible time which is accomplished by drawing ofi the grease through the outlet l3 leading from the dome I2. This outlet conduit for grease accumulation is provided with a cutoff valve l3 to be opened from time to time as determined by the accumulation of grease within the dome.

' As the cooking operation continues, the gelatinous material is released and dissolved from the stock until the cooking water or liquor becomes a quite concentrated solution. With the present apparatus and method of operation, a much greater proportion of the gelatin may be extracted within a given period and hence the liquor becomes more highly concentrated than is usual. This is quite desirable since it effects a very much greater extraction of gelatin as first run liquor which produces the most desirable product and of greater commercial value. The tank or vessel is preferably provided with automatic density regulating means by which the liquor may be drawn off automatically whenever the density reaches a predetermined point and fresh water added in like quantity. The gelatin solution is drawn from the tank through a discharge conduit 26 which communicates with the outer compartment 9. The material being confined within the inner perforated compartment 6 and subject to the action of the cooking liquor therein, only gelatin charged liquor will be found in the outer compartment 9. The cooking liquor circulates freely between the compartments 6 and 9 through the perforations of the side walls 8 of the inner compartment.

The apparatus may be utilized in an intermittent process wherein the treatment of the stock is interrupted when the extracting liquid has acquired the desired density and is ready to be drawn off through the outlet conduit 26 after which fresh water or liquid is added and the process continued until a similar degree of density or concentration is achieved and the liquor again drawn 011. These operations are repeated, each succeeding extraction being at somewhat higher temperatures until all of the colloidal matter in the stock under treatment isextracted. In lieu thereof the process may be operated as a continuous operation by providing automatic density control means by whichthe liquor is drawn off automatically whenever the density reaches a predetermined point and fresh water automatically added in like proportion. The freshly added water or liquor being discharged into the center of the mass of material under treatment, does not dilute the concentrated liquor in the .outer compartment 9, but takes up in solution additional gelatin as it circulates from the center of the mass outwardly, becoming in turn a highly concentrated solution of gelatin.

When the stock has been sufficiently treated and all available colloidal matter andgrease extracted and concentrated liquor drawn oif, the residue is removed from the compartment 6 through a door 21 in the end wall or head of the tank I at the lower end of theinclined compartment. Such material may be easily and rapidly withdrawn by means of a rake. By opening the lower drain or draw-off outlet 25, finely divided particles which may have settled to the bottom 01' the tank are removed and the apparatus may be thoroughly cleansed and washed by admitting water under pressure through the inlet conduit at the upper end of the inclined tank or vessel, and after agitating the wash water it is drained through the outlet drain at the lower end. If desired, live steam may be discharged through the tank in a similar manner. The apparatus is then again ready for repetition of the operation. The material under treatment being confined to the inner compartment and subjected to slow uniform agitation during the cooking period, rapid and complete extraction of the gelatinous content is eifected, the concentrated liquor passing freely thence through the perforation in the side walls 8 of the inner compartment to be drawn oif from the outer compartment 9, producing a very clear and desirable product of high quality. In the event that the last extracted portion or runs of gelatin liquor are cloudy, such liquor may be filtered or clarified chemically.

After the extraction, the gelatin solution is further concentrated by evaporation into a jelly like condition which is then spread into sheet form or such jelly is molded into blocks and subsequently sliced and dried either by blowers or exhaust fans, or in kilns. The steps of spreading and desiccation and final grinding or finishing form no part of the present invention and hence have not been described in detail.

While the invention has been heretofore described more particularly in its application to the extraction of gelatin and recovery of grease from animal products, it is to be understood that it is not limited to such application, but, as before mentioned, is well adapted for rendering packinghouse and fishery offal for recovery of grease and by-products', and will find a further wide range of usefulness in the liberation of vegetable oils from such material as copra, soy beans, castor beans, sesame seeds and kindred oil bearing vegetable growth, nuts and seeds. Such vegetable matter may be treated in quite the same manner asbefore described by slow cooking while the material is being agitated to rupture and break down the cellular tissue, therebyallowing the oil to escape and rise to the top of the cooking liquor where it can be drained off as in the case of animal matter reduction. The cooking liquor may be drawn ofl for recovery of sugars and other by-products. Instead of so treating the vegetable matter in the first instance, the material may be first subjected to pressure, as is the present practice, forextraction of the vegetable oil after which the pomace may be subjected to the cooking and agitating operation by which the-remaining oil will be extracted.

Instead of flooding the tank and floating the extracted vegetable oils to the top to be drawn oil through the grease outlet l3, the ground ma-' terial may be sprayed with water or with other extracting liquid or solvent while being agitated within the compartment 6 and the resulting solution or mixture of water and extracted material may be withdrawn through the drain outlet as the extraction progresses.

While for illustrative purposes, heater coils l5 have been illustrated in the bottom of the compartment 9, it will be understood that other means of supplying-the necessary heat may be employed, as for example the outer tank I may be formed with a double wall or steam jacket through which live steam is circulated, or flame,

may be externally applied directly to the bottom of the tank I.

While the present apparatus has been described in its application to cooking the material for extraction of the gelatin, it is to be understood that the apparatus is usable with equal facility for preparing the material for extraction. The material may be given its preliminary washing, and be subsequently iimed, washed acidulated, and rewashed in the present apparatus prior to the cooking or extraction operation. Thus much handling of the material is eliminated and the necessity forv steeping vats, washing and other treatment apparatus is eliminated. The entire preparation and extraction process can be carried out in the present apparatus with greater rapidity, with less equipment, in less space, and with minimum labor and attention, while at the same time producing a much greater quantity of higher grade product of increased commercial value. I

Although the construction heretofore described, is the preferred commercial form of the apparatus, it will be quite obvious that the invention may be embodied in other forms.

In Figs. 4 and 5 there is shown a modification wherein the main tank is not provided with an inner compartment, as heretofore described, but in lieu thereof it is provided with one or more lateral bays or extensions 28 communicating with the interior of the tank or vat through, a perforated or screen wall 29. The agitator comprising the bars 22 carried upon arms 2i rotate within the'main tank to which water is supplied .such collecting bays are provided, the off-take conduit 26 may communicate with all of them as is shown in the plan view, Fig. 5. In the event that a supply conduit 30 is employed for admitting water to the tank during treatment, the agitator shaft l6 need not be hollow. In Fig. 6 there is shown a further modification wherein, in lieu of the inner compartment 6 having a semi-circular bottom I and vertical side walls 8, there is provided a rotary drum or compartment 3i revoluble about its longitudinal axis and having perforated walls communicating with the interior of the main tank 1 outside such revoluble perforatedcontainer. This revoluble compartment 3| is provided with a charging door 32 and also provided in one end with a discharge door 21 through which the residue of material may be removed.

The operation and function of the apparatus is as before described, the primary difference being that instead of providing the stationary inner compartment 6 having vertical perforated side walls 8 and providing a rotating agitator within the compartments 8, in the present modification the compartment itself is made to revolve and hence no agitator is required. By rotating the perforated cylindrical inner compartment or container 3!, the material therein is tumbled and agitated so that the cooking liquor reaches every portion thereof.

While a horizontal type of apparatus has been adopted for commercial manufacture, the invention may be embodied with equal iacility in a vertical type of apparatus as is illustrated in Fig. '7. In this construction the outer tank I is pro-- vided with the grease dome i2 at its top and interiorly of the tank is provided an inner compartpartment and outer wall of the vat I, will rise within the inner compartment, overflowing the top thereof through the perforated walls 36 and descend through the outer space. However, by providing auxiliary heater coils 33 in the in-' termediate space between the inner compartment wall 35 and the outer wall of the tank i, this direction of circulation may be reversed, and by heating the cooking liquor, it may be caused to rise outside the cooking compartment and entering the top of the inner compartment through the perforate walls 36 descend therethrough as indicated by the arrows in Fig. 7, dissolving and entraining in its course the released gelatin.

Fig. 8 illustrates a still further modification wherein the compartment is transversely divided by a transverse partition wall 39 thereby providing a collecting compartment 40 in the bottom of the main tank, above which the material is cooked and agitated in much the same manner as in Fig. 7. -Fig. 8 illustrates the tank as being jacketed or formed with a double wall for the circulation of steam within such double wall in lieu of the heater coils l5.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable,

but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute, the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise the preferred form of several modes of putting the invention into effect, and the invention is therefore claimed in any of its forms or modiiications within the legitimate and valid scope of the appended claims.

Having thus described my invention, I claim:

1. In an apparatus of the character described, a pair of horizontal concentric vessels having parallel, spaced'side and bottom walls, the walls of the inner vessel being perforated for intercommunication of the'contents of the two vessels therethrough, a cover for said vessels having an inclined top, a grease collecting dome at the top of the inclined top, a grease discharge conduit conduit for the cooking'liquor communicating with the space intermediate the vessel walls.

2. In an apparatus of the character described, a stationary tank, a partition within the tank forming an inner compartment having a substantially semicircular bottom inclined slightly to the horizontal, the walls and bottom of which are spaced from the tank walls and bottom to form an intermediatecompartment for collection of liquids, the side walls of such inner compartment being perforated, an inclined top for the tank, a dome of restricted cross-sectional area surmounting the apex of the inclined top of the vat, a grease outlet conduitleading from the dome, a hollow revoluble shaft extending substantially horizontally through the inner compartment of the tank, a water supply connection leading to the hollow shaft, said shaft having lateral discharge ports therein, agitator means carried by the revoluble shaft, means for heating the contents of the tank, and a discharge conduit for liquid communicating with the compartment between the tank wall and the partition at a point elevated above the bottom of the compartment.

3. In an apparatus of the character described, a horizontally disposed cooker compartment of substantially U-shaped cross-section, the bottom of which is slightly inclined to the horizontal, and having perforated side walls, a collecting comshaped cross-section, the bottom of which is longitudinally inclined, and the side walls of which are perforated, an exterior compartment enclosing the first mentioned compartment with which the main compartment communicates through such perforations, means including heating coils for heating the main compartment, and agitator means therein rotating about a horizontal axis.

5. In a rendering apparatus for extracting gelatin and the like, a pair of concentric vessels having their side walls and bottoms arranged in relatively spaced relation, the side wall of the inner vessel extending upwardly to the top of the outer vessel andbeing perforated to permit communication between said vessels, a horizontal rotatable shaft extending through said inner vessel, agitator means carried by said shaft, heating means interposed between the vessels for heating the contents thereof during agitation, a conduit for supplying liquid to the inner vessel, and an outlet conduit connected to the side wall of the outer vessel at a point substantially level with said agitator shaft.

6. In a rendering apparatus for extracting gelatin and the like, a pair of concentric vessels disposed in relatively spaced relation, the top of the inner vessel terminating on substantially the same plane with the top of the outer vessel and being perforated adjacent its upper end to permit communication between said vessels, a horizontal rotatable shaft extending through said inner vessel between the ends of the latter, agitator means carried by said shaft, heating means disposed between the vessels for heating the contents thereof during agitation, a conduit for supplying liquid to the inner vessel and an outlet conduit connected to the side wall of the outer vessel at a point above said agitator shaft.

7. In a rendering apparatus for extracting gelatinand the like, a pair of concentric vessels disposed in relatively spaced relation, the top of the inner vessel terminating in substantially the same plane with the top of the outer vessel, the

vertical walls of the inner. vessel being perforated to permit communication between said vessels, a rotatable shaft extending through said vessel, agitator means can'ied by said shaft, means for heating the contents of the inner vessel during agitation, a conduit for supplying liquid to the inner vessel and an outlet conduit connected to the outer wall at a point substantially midway between the top and bottom thereof.

v. KNOLL. 

